[linux-2.6-block.git] / arch / powerpc / platforms / pseries / smp.c

/*
 * SMP support for pSeries machines.
 *
 * Dave Engebretsen, Peter Bergner, and
 * Mike Corrigan {engebret|bergner|mikec}@us.ibm.com
 *
 * Plus various changes from other IBM teams...
 *
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 */


#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/cache.h>
#include <linux/err.h>
#include <linux/device.h>
#include <linux/cpu.h>

#include <asm/ptrace.h>
#include <linux/atomic.h>
#include <asm/irq.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/io.h>
#include <asm/prom.h>
#include <asm/smp.h>
#include <asm/paca.h>
#include <asm/machdep.h>
#include <asm/cputable.h>
#include <asm/firmware.h>
#include <asm/rtas.h>
#include <asm/mpic.h>
#include <asm/vdso_datapage.h>
#include <asm/cputhreads.h>
#include <asm/xics.h>

#include "plpar_wrappers.h"
#include "pseries.h"
#include "offline_states.h"


/*
 * The Primary thread of each non-boot processor was started from the OF client
 * interface by prom_hold_cpus and is spinning on secondary_hold_spinloop.
 */
static cpumask_var_t of_spin_mask;

/* Query where a cpu is now.  Return codes #defined in plpar_wrappers.h */
int smp_query_cpu_stopped(unsigned int pcpu)
{
	int cpu_status, status;
	int qcss_tok = rtas_token("query-cpu-stopped-state");

	if (qcss_tok == RTAS_UNKNOWN_SERVICE) {
		printk_once(KERN_INFO
			"Firmware doesn't support query-cpu-stopped-state\n");
		return QCSS_HARDWARE_ERROR;
	}

	status = rtas_call(qcss_tok, 1, 2, &cpu_status, pcpu);
	if (status != 0) {
		printk(KERN_ERR
		       "RTAS query-cpu-stopped-state failed: %i\n", status);
		return status;
	}

	return cpu_status;
}

/**
 * smp_startup_cpu() - start the given cpu
 *
 * At boot time, there is nothing to do for primary threads which were
 * started from Open Firmware.  For anything else, call RTAS with the
 * appropriate start location.
 *
 * Returns:
 *	0	- failure
 *	1	- success
 */
static inline int smp_startup_cpu(unsigned int lcpu)
{
	int status;
	unsigned long start_here = __pa((u32)*((unsigned long *)
					       generic_secondary_smp_init));
	unsigned int pcpu;
	int start_cpu;

	if (cpumask_test_cpu(lcpu, of_spin_mask))
		/* Already started by OF and sitting in spin loop */
		return 1;

	pcpu = get_hard_smp_processor_id(lcpu);

	/* Check to see if the CPU out of FW already for kexec */
	if (smp_query_cpu_stopped(pcpu) == QCSS_NOT_STOPPED){
		cpumask_set_cpu(lcpu, of_spin_mask);
		return 1;
	}

	/* Fixup atomic count: it exited inside IRQ handler. */
	task_thread_info(paca[lcpu].__current)->preempt_count	= 0;
#ifdef CONFIG_HOTPLUG_CPU
	if (get_cpu_current_state(lcpu) == CPU_STATE_INACTIVE)
		goto out;
#endif
	/* 
	 * If the RTAS start-cpu token does not exist then presume the
	 * cpu is already spinning.
	 */
	start_cpu = rtas_token("start-cpu");
	if (start_cpu == RTAS_UNKNOWN_SERVICE)
		return 1;

	status = rtas_call(start_cpu, 3, 1, NULL, pcpu, start_here, pcpu);
	if (status != 0) {
		printk(KERN_ERR "start-cpu failed: %i\n", status);
		return 0;
	}

#ifdef CONFIG_HOTPLUG_CPU
out:
#endif
	return 1;
}

static void smp_xics_setup_cpu(int cpu)
{
	if (cpu != boot_cpuid)
		xics_setup_cpu();

	if (firmware_has_feature(FW_FEATURE_SPLPAR))
		vpa_init(cpu);

	cpumask_clear_cpu(cpu, of_spin_mask);
#ifdef CONFIG_HOTPLUG_CPU
	set_cpu_current_state(cpu, CPU_STATE_ONLINE);
	set_default_offline_state(cpu);
#endif
}

static int smp_pSeries_kick_cpu(int nr)
{
	BUG_ON(nr < 0 || nr >= NR_CPUS);

	if (!smp_startup_cpu(nr))
		return -ENOENT;

	/*
	 * The processor is currently spinning, waiting for the
	 * cpu_start field to become non-zero After we set cpu_start,
	 * the processor will continue on to secondary_start
	 */
	paca[nr].cpu_start = 1;
#ifdef CONFIG_HOTPLUG_CPU
	set_preferred_offline_state(nr, CPU_STATE_ONLINE);

	if (get_cpu_current_state(nr) == CPU_STATE_INACTIVE) {
		long rc;
		unsigned long hcpuid;

		hcpuid = get_hard_smp_processor_id(nr);
		rc = plpar_hcall_norets(H_PROD, hcpuid);
		if (rc != H_SUCCESS)
			printk(KERN_ERR "Error: Prod to wake up processor %d "
						"Ret= %ld\n", nr, rc);
	}
#endif

	return 0;
}

static int smp_pSeries_cpu_bootable(unsigned int nr)
{
	/* Special case - we inhibit secondary thread startup
	 * during boot if the user requests it.
	 */
	if (system_state < SYSTEM_RUNNING && cpu_has_feature(CPU_FTR_SMT)) {
		if (!smt_enabled_at_boot && cpu_thread_in_core(nr) != 0)
			return 0;
		if (smt_enabled_at_boot
		    && cpu_thread_in_core(nr) >= smt_enabled_at_boot)
			return 0;
	}

	return 1;
}

static struct smp_ops_t pSeries_mpic_smp_ops = {
	.message_pass	= smp_mpic_message_pass,
	.probe		= smp_mpic_probe,
	.kick_cpu	= smp_pSeries_kick_cpu,
	.setup_cpu	= smp_mpic_setup_cpu,
};

static struct smp_ops_t pSeries_xics_smp_ops = {
	.message_pass	= NULL,	/* Use smp_muxed_ipi_message_pass */
	.cause_ipi	= NULL,	/* Filled at runtime by xics_smp_probe() */
	.probe		= xics_smp_probe,
	.kick_cpu	= smp_pSeries_kick_cpu,
	.setup_cpu	= smp_xics_setup_cpu,
	.cpu_bootable	= smp_pSeries_cpu_bootable,
};

/* This is called very early */
static void __init smp_init_pseries(void)
{
	int i;

	pr_debug(" -> smp_init_pSeries()\n");

	alloc_bootmem_cpumask_var(&of_spin_mask);

	/* Mark threads which are still spinning in hold loops. */
	if (cpu_has_feature(CPU_FTR_SMT)) {
		for_each_present_cpu(i) { 
			if (cpu_thread_in_core(i) == 0)
				cpumask_set_cpu(i, of_spin_mask);
		}
	} else {
		cpumask_copy(of_spin_mask, cpu_present_mask);
	}

	cpumask_clear_cpu(boot_cpuid, of_spin_mask);

	/* Non-lpar has additional take/give timebase */
	if (rtas_token("freeze-time-base") != RTAS_UNKNOWN_SERVICE) {
		smp_ops->give_timebase = rtas_give_timebase;
		smp_ops->take_timebase = rtas_take_timebase;
	}

	pr_debug(" <- smp_init_pSeries()\n");
}

void __init smp_init_pseries_mpic(void)
{
	smp_ops = &pSeries_mpic_smp_ops;

	smp_init_pseries();
}

void __init smp_init_pseries_xics(void)
{
	smp_ops = &pSeries_xics_smp_ops;

	smp_init_pseries();
}
Commit	Line	Data
	1	/*
	2	* SMP support for pSeries machines.
	3	*
	4	* Dave Engebretsen, Peter Bergner, and
	5	* Mike Corrigan {engebret\|bergner\|mikec}@us.ibm.com
	6	*
	7	* Plus various changes from other IBM teams...
	8	*
	9	* This program is free software; you can redistribute it and/or
	10	* modify it under the terms of the GNU General Public License
	11	* as published by the Free Software Foundation; either version
	12	* 2 of the License, or (at your option) any later version.
	13	*/
	14
	15
	16	#include <linux/kernel.h>
	17	#include <linux/sched.h>
	18	#include <linux/smp.h>
	19	#include <linux/interrupt.h>
	20	#include <linux/delay.h>
	21	#include <linux/init.h>
	22	#include <linux/spinlock.h>
	23	#include <linux/cache.h>
	24	#include <linux/err.h>
	25	#include <linux/device.h>
	26	#include <linux/cpu.h>
	27
	28	#include <asm/ptrace.h>
	29	#include <linux/atomic.h>
	30	#include <asm/irq.h>
	31	#include <asm/page.h>
	32	#include <asm/pgtable.h>
	33	#include <asm/io.h>
	34	#include <asm/prom.h>
	35	#include <asm/smp.h>
	36	#include <asm/paca.h>
	37	#include <asm/machdep.h>
	38	#include <asm/cputable.h>
	39	#include <asm/firmware.h>
	40	#include <asm/rtas.h>
	41	#include <asm/mpic.h>
	42	#include <asm/vdso_datapage.h>
	43	#include <asm/cputhreads.h>
	44	#include <asm/xics.h>
	45
	46	#include "plpar_wrappers.h"
	47	#include "pseries.h"
	48	#include "offline_states.h"
	49
	50
	51	/*
	52	* The Primary thread of each non-boot processor was started from the OF client
	53	* interface by prom_hold_cpus and is spinning on secondary_hold_spinloop.
	54	*/
	55	static cpumask_var_t of_spin_mask;
	56
	57	/* Query where a cpu is now. Return codes #defined in plpar_wrappers.h */
	58	int smp_query_cpu_stopped(unsigned int pcpu)
	59	{
	60	int cpu_status, status;
	61	int qcss_tok = rtas_token("query-cpu-stopped-state");
	62
	63	if (qcss_tok == RTAS_UNKNOWN_SERVICE) {
	64	printk_once(KERN_INFO
	65	"Firmware doesn't support query-cpu-stopped-state\n");
	66	return QCSS_HARDWARE_ERROR;
	67	}
	68
	69	status = rtas_call(qcss_tok, 1, 2, &cpu_status, pcpu);
	70	if (status != 0) {
	71	printk(KERN_ERR
	72	"RTAS query-cpu-stopped-state failed: %i\n", status);
	73	return status;
	74	}
	75
	76	return cpu_status;
	77	}
	78
	79	/**
	80	* smp_startup_cpu() - start the given cpu
	81	*
	82	* At boot time, there is nothing to do for primary threads which were
	83	* started from Open Firmware. For anything else, call RTAS with the
	84	* appropriate start location.
	85	*
	86	* Returns:
	87	* 0 - failure
	88	* 1 - success
	89	*/
	90	static inline int smp_startup_cpu(unsigned int lcpu)
	91	{
	92	int status;
	93	unsigned long start_here = __pa((u32)((unsigned long )
	94	generic_secondary_smp_init));
	95	unsigned int pcpu;
	96	int start_cpu;
	97
	98	if (cpumask_test_cpu(lcpu, of_spin_mask))
	99	/* Already started by OF and sitting in spin loop */
	100	return 1;
	101
	102	pcpu = get_hard_smp_processor_id(lcpu);
	103
	104	/* Check to see if the CPU out of FW already for kexec */
	105	if (smp_query_cpu_stopped(pcpu) == QCSS_NOT_STOPPED){
	106	cpumask_set_cpu(lcpu, of_spin_mask);
	107	return 1;
	108	}
	109
	110	/* Fixup atomic count: it exited inside IRQ handler. */
	111	task_thread_info(paca[lcpu].__current)->preempt_count = 0;
	112	#ifdef CONFIG_HOTPLUG_CPU
	113	if (get_cpu_current_state(lcpu) == CPU_STATE_INACTIVE)
	114	goto out;
	115	#endif
	116	/*
	117	* If the RTAS start-cpu token does not exist then presume the
	118	* cpu is already spinning.
	119	*/
	120	start_cpu = rtas_token("start-cpu");
	121	if (start_cpu == RTAS_UNKNOWN_SERVICE)
	122	return 1;
	123
	124	status = rtas_call(start_cpu, 3, 1, NULL, pcpu, start_here, pcpu);
	125	if (status != 0) {
	126	printk(KERN_ERR "start-cpu failed: %i\n", status);
	127	return 0;
	128	}
	129
	130	#ifdef CONFIG_HOTPLUG_CPU
	131	out:
	132	#endif
	133	return 1;
	134	}
	135
	136	static void smp_xics_setup_cpu(int cpu)
	137	{
	138	if (cpu != boot_cpuid)
	139	xics_setup_cpu();
	140
	141	if (firmware_has_feature(FW_FEATURE_SPLPAR))
	142	vpa_init(cpu);
	143
	144	cpumask_clear_cpu(cpu, of_spin_mask);
	145	#ifdef CONFIG_HOTPLUG_CPU
	146	set_cpu_current_state(cpu, CPU_STATE_ONLINE);
	147	set_default_offline_state(cpu);
	148	#endif
	149	}
	150
	151	static int smp_pSeries_kick_cpu(int nr)
	152	{
	153	BUG_ON(nr < 0 \|\| nr >= NR_CPUS);
	154
	155	if (!smp_startup_cpu(nr))
	156	return -ENOENT;
	157
	158	/*
	159	* The processor is currently spinning, waiting for the
	160	* cpu_start field to become non-zero After we set cpu_start,
	161	* the processor will continue on to secondary_start
	162	*/
	163	paca[nr].cpu_start = 1;
	164	#ifdef CONFIG_HOTPLUG_CPU
	165	set_preferred_offline_state(nr, CPU_STATE_ONLINE);
	166
	167	if (get_cpu_current_state(nr) == CPU_STATE_INACTIVE) {
	168	long rc;
	169	unsigned long hcpuid;
	170
	171	hcpuid = get_hard_smp_processor_id(nr);
	172	rc = plpar_hcall_norets(H_PROD, hcpuid);
	173	if (rc != H_SUCCESS)
	174	printk(KERN_ERR "Error: Prod to wake up processor %d "
	175	"Ret= %ld\n", nr, rc);
	176	}
	177	#endif
	178
	179	return 0;
	180	}
	181
	182	static int smp_pSeries_cpu_bootable(unsigned int nr)
	183	{
	184	/* Special case - we inhibit secondary thread startup
	185	* during boot if the user requests it.
	186	*/
	187	if (system_state < SYSTEM_RUNNING && cpu_has_feature(CPU_FTR_SMT)) {
	188	if (!smt_enabled_at_boot && cpu_thread_in_core(nr) != 0)
	189	return 0;
	190	if (smt_enabled_at_boot
	191	&& cpu_thread_in_core(nr) >= smt_enabled_at_boot)
	192	return 0;
	193	}
	194
	195	return 1;
	196	}
	197
	198	static struct smp_ops_t pSeries_mpic_smp_ops = {
	199	.message_pass = smp_mpic_message_pass,
	200	.probe = smp_mpic_probe,
	201	.kick_cpu = smp_pSeries_kick_cpu,
	202	.setup_cpu = smp_mpic_setup_cpu,
	203	};
	204
	205	static struct smp_ops_t pSeries_xics_smp_ops = {
	206	.message_pass = NULL, /* Use smp_muxed_ipi_message_pass */
	207	.cause_ipi = NULL, /* Filled at runtime by xics_smp_probe() */
	208	.probe = xics_smp_probe,
	209	.kick_cpu = smp_pSeries_kick_cpu,
	210	.setup_cpu = smp_xics_setup_cpu,
	211	.cpu_bootable = smp_pSeries_cpu_bootable,
	212	};
	213
	214	/* This is called very early */
	215	static void __init smp_init_pseries(void)
	216	{
	217	int i;
	218
	219	pr_debug(" -> smp_init_pSeries()\n");
	220
	221	alloc_bootmem_cpumask_var(&of_spin_mask);
	222
	223	/* Mark threads which are still spinning in hold loops. */
	224	if (cpu_has_feature(CPU_FTR_SMT)) {
	225	for_each_present_cpu(i) {
	226	if (cpu_thread_in_core(i) == 0)
	227	cpumask_set_cpu(i, of_spin_mask);
	228	}
	229	} else {
	230	cpumask_copy(of_spin_mask, cpu_present_mask);
	231	}
	232
	233	cpumask_clear_cpu(boot_cpuid, of_spin_mask);
	234
	235	/* Non-lpar has additional take/give timebase */
	236	if (rtas_token("freeze-time-base") != RTAS_UNKNOWN_SERVICE) {
	237	smp_ops->give_timebase = rtas_give_timebase;
	238	smp_ops->take_timebase = rtas_take_timebase;
	239	}
	240
	241	pr_debug(" <- smp_init_pSeries()\n");
	242	}
	243
	244	void __init smp_init_pseries_mpic(void)
	245	{
	246	smp_ops = &pSeries_mpic_smp_ops;
	247
	248	smp_init_pseries();
	249	}
	250
	251	void __init smp_init_pseries_xics(void)
	252	{
	253	smp_ops = &pSeries_xics_smp_ops;
	254
	255	smp_init_pseries();
	256	}